A gunman opened fire on an outdoor country music festival in Las Vegas, killing at least 59 and injuring more than 515, according to reports, in the worst mass shooting in modern U.S. history.

Mass shooting at Mandalay Bay Hotel and Casino in Las Vegas

Gunman's Mandalay Bay hotel room

The Las Vegas Metropolitan Police Department released never-before-seen photos from inside the Mandalay Bay hotel room where gunman Stephen Paddock opened fire on the Route 91 Harvest Music Festival on Oct. 1, 2017, in Las Vegas, Nevada. The gunman, whose body has been censored in this photo, killed 59 and injured more than 515, in the worst mass shooting in modern U.S. history.